This invention relates to the mounting of traction gear on the bottom of footwear, in particular, athletic footwear.
Conventional traction gear presently in use employ an attachment means consisting of screwing the traction gear into the mated receiving receptacle in the bottom of the footwear. Using this screw-type attachment method is especially laborious when one takes into account that a typical golf shoe, for instance, has eleven cleats; as a result, replacing the cleats on a pair of golf shoes entails unscrewing twenty-two cleats and screwing on twenty-two cleats, where each act of unscrewing or screwing entails several turns, typically two and one-half times, for each cleat.
An example of a typical prior-art cleat is in U.S. Pat. No. 4,723,366 (hereinafter the ""366 cleat), which patent is incorporated herein by reference. This patent describes a cleat which includes a metal stud infrastructure at the core of the cleat, the infrastructure having a vertical axis and two ends, a screw portion at a first end for engagement with a receptacle within a shoe, a ground end for tractive engagement with the ground, and a broad flange between the screw and head portions and extending radially outward from the vertical axis; a plastic skirt is molded directly upon the flange portion to form a unitary reinforced radial support member of the cleat. Installation of the ""366 cleat consists of screwing it into a mated receptacle in the bottom of athletic footwear.
Although some prior-art references show cleat-attachment systems that require less than a full turn, or they require a snap-on arrangement to lock the cleat in place, it appears none of these systems have found wide acceptance amongst users because of shortcomings in stability, ease-of-use, receptacle size and ease-of-manufacture. For instance, in U.S. Pat. No. 4,633,600 to Dassler, a cleat attachment system is disclosed in which a snap ring socket is utilized to affix a cleat to the bottom of a shoe.
In U.S. Pat. No. 3,267,593 to Turner, a cleat attachment system is disclosed wherein the top of the cleat spike has two extensions forming a rough T-shape out of the spike, where the spike is inserted into a mated receptacle having two grooves to receive the extensions. Upon complete insertion of the spike into a receptacle, the spike is turned until the extensions drop into receiving grooves at the top of the receptacle; a retaining ring is then slid onto the mid-section of the spike, this ring apparently preventing the spike from unseating the extensions from the grooves.
Similarly, in German Patent Application Nos. DE3134817A1 to Sportartikelfabrik Karl Uhl GmbH, and DE3423363A1 to Gebrxc3xcder Goldschmidt Baubeschlxc3xa4ge GmbH, another T-spike design is disclosed in which internal to the mated receptacle are ramping means for engaging and retaining the spike extensions. In the former, a rough interior surface catches the extensions, while in the latter, a sloping interior engages the extensions.
U.S. Pat. No. 4,492,047 to Arff, discloses another T-shape spike in which the skirt is deformed during insertion. Insertion of the spike causes the extensions to go up a ramp and then down a ramp, pulling the spike into the receptacle, and leaving the extensions in a holding area. The skirt is deformed so as to result in a pressure against the socket, the pressure apparently holding the spike from accidentally traveling back up the ramp towards removal.
In U.S. Pat. No. 4,035,934 to Hrivnak, another T-shape spike is disclosed in which the spike column has two indentations. During installation, two spring arms, each positioned perpendicular to the surface of the shoe and parallel to the spike, are pressed in during insertion of the spike, and spring back out to press against the indentations upon complete insertion. Removal of this spike is achieved with a U-shaped tool which slides into the spike receptacle and pushes in the spring arms, thus freeing the spike for removal.
The present invention provides a system for removably attaching traction gear to the underside of footwear. This system includes two primary components: a retaining member and a receptacle. In a preferred embodiment of the invention, these two components respectively replace the common screw and threaded receptacle system for affixing traction gear to the underside of shoes, providing a faster and simpler attachment of the cleat. Only a partial turn of about 60 degrees of the traction gear securely locks the gear into the receptacle. The three-extension design of a preferred embodiment of the invention makes the traction gear resistant to lateral forces applied to the ground-engaging end of the cleat. Although one embodiment of the invention is a skirted spike utilizing the attachment system for attachment to a golf shoe, other types of traction gear, such as that for rock climbing, may employ the same attachment system.
The present invention employs a three-extension quick-release system for attaching cleats to footwear, instead of the conventional screw method, snap-ring, or T-shaped retaining member of prior-art cleats; with the quick-release system, one can place a cleat into a receptacle in the bottom of a shoe, and simply give the cleat a partial turn to lock it into place for use. (References herein and within the claims that follow to the xe2x80x9ctopxe2x80x9d and xe2x80x9cbottomxe2x80x9d respectively refer to the end nearer the wearer""s foot, and the end nearer the ground.)
A cleat according to the present invention includes a base, preferably made of metal and/or plastic, where at the bottom of the base is standard traction gear, such as the skirt and spike of a golf cleat, and at the top of the base is additional structure for attaching the traction gear to a shoe. The skirt may extend radially outward beyond the ends of the attaching structure and may include full or partial apertures for receiving a cleat wrench, which may be used to install and remove the cleat. The gripping member may be plastic, metal, or have a metal core with a plastic outer layer. Attachment is achieved through use of several extensions projecting out from the top of the base at right angles to the base. In a preferred embodiment of the invention, three thermoplastic extensions are used, all of which are in the same plane, and each extension is equidistant from adjacent extensions. Each extension has a front side and a back side, each of which is substantially parallel to a radial midline of the extension, with the back side defining an indentation which may be L-shaped. If a cleat using this invention were turned upside down, i.e. ground tip up, it would appear that the cleat was standing on a roughly triangular base formed of the three extensions.
To use the invention, an athletic shoe would contain receptacles in the bottom of the shoe designed to receive the cleat. Each receptacle has a wall defining a cavity between a receptacle top and a receptacle bottom, a restraining means attached to the receptacle bottom and extending into the cavity so as to prevent downward movement of an installed cleat, stopping means within the cavity to engage a front side of an extension and prevent the extension from rotating past the stopping means, and a plurality of protuberances within the cavity to engage a back side of an extension and resist rotation of the extension past the protuberance. A cleat inserted into the cavity may be rotated so that the front side of an extension compresses a protuberance to allow the extension to rotate past the protuberance until the front side of the extension contacts a stopping means and the protuberance snugly engages the back side of the extension. In a preferred embodiment, the protuberances are in substantially the same plane as the extension. In a preferred embodiment, the restraining means may include a lip formed at the bottom of the restraining means, against which an outer edge of a top surface of the cleat may overlap in a keyed fashion.
In addition, to ensure a tight fit, and to help prevent dirt and grime from getting inside the receptacle, the extensions and receptacle are preferably designed so that as a cleat is turned within a receptacle, the space for the extension gets tighter, thus compressing the extensions during installation. In a preferred embodiment, this tightening may be accomplished by a taper on the front side of the radial ends of the extensions. The protuberances may be shaped so as to permit turning the cleat with significantly less force during installation than is required for removal. In addition, located at the top of the receptacle may be a resilient bubble partially filling the receptacle, this bubble has a certain resiliency or elasticity, such that the bubble is compressed during insertion of the cleat within the receptacle. When the cleat locks into place, the tight fit and use of three extensions within a receptacle, in addition to the downward pressure from the compressed bubble, renders the cleat very stable.
Removal of the cleat is achieved by simply turning the cleat in the opposite direction of installation. The compressed bubble then aids removal of the cleat, and the expansion of the bubble during removal helps eject the spike from the receptacle. The preferred design of the locking mechanism is such that it takes much more force to turn against the lock than it took to install a cleat.
In a preferred embodiment, a cleat using this system is made out of plastic with internal metal reinforcement; an all-metal design, or a design using resin or another tough material, may be used. Some materials that may be used to form traction gear according to the present invention include but are not limited to thermoplastic materials such as Stanyl Nylon 46, Dupont Acetal Resin 100ST, Technyl A216, Noryl GTX 810, Noryl GTX 820, Polyurethane S74D, Polyurethane 90A, Nylon 6, Nylon 6/6, and Rython. In the present invention, use of such materials to form the extensions with a metal core in the base is preferred as this design allows for extensions that are actually bigger than the space for them inside the receptacle, so that installing a cleat compresses and squeezes the extensions so that a very tight fit results.
Other preferred embodiments include a sole of a shoe having at least one receptacle as described above. Another related embodiment comprises a method of manufacturing such a receptacle for instance by producing the receptacle on a horizontal press.
A preferred embodiment is also directed to a method of installing a removable cleat to the sole of a shoe. In such an embodiment, the method includes providing a cleat having a gripping member for engaging the ground and a retaining means for removably attaching the cleat to the footwear, the retaining means having a vertical axis, a base to which the top of the gripping member is attached, and at least three extensions attached to the base, wherein each extension projects radially outward from the base in a direction substantially perpendicular to the vertical axis, and wherein each extension has a front side and a back side, each side substantially parallel to a radial midline of the extension, the back side defining an indentation. A preferred embodiment continues by providing a receptacle for receiving and holding the cleat, the receptacle being mounted in the sole of a shoe, the receptacle having a wall defining a cavity between a receptacle top and a receptacle bottom, a restraining means attached to the receptacle bottom and extending into the cavity so as to prevent downward movement of an installed cleat, stopping means within the cavity to engage a front side of an extension and prevent the extension from rotating past the stopping means, and a plurality of protuberances within the cavity to engage a back side of an extension and resist rotation of the extension past the protuberance. A cleat inserted into the cavity may be rotated so that the front side of an extension compresses a protuberance to allow the extension to rotate past the protuberance until the front side of the extension contacts a stopping means and the protuberance snugly engages the back side of the extension. The method continues with inserting the cleat""s extensions into the receptacle""s cavity and rotating the cleat until the cleat reaches a locked position.